The remote control of surface properties is one of the key challenges in interfacial systems chemistry. Here, we report the realization of a SURMOF (surface-mounted metal-organic framework)-based hybrid system in which a crucial component can be switched by light. The realization of this two-component system is made possible by installing vertical compositional gradients via liquid-phase epitaxy. After loading the porous coating with guest molecules, its release is initiated by illumination with visible light and monitored by a quartz crystal microbalance.

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In this article, we use the popular photoswitchable molecule, azobenzene, to demonstrate that the embedding in a nanoporous, crystalline solid enables a precise understanding of light-induced, reversible molecular motion. We investigate two similar azobenzene-containing, pillared-layer metal-organic frameworks (MOFs): Cu2(AzoBPDC)2(BiPy) and Cu2(NDC)2(AzoBiPy). Experimental results from UV-vis spectroscopy and molecular uptake experiments as well as theoretical results based on density-functional theory (DFT) show that in the Cu2(AzoBPDC)2(BiPy) MOF structure, the azobenzene side groups undergo photoisomerization when irradiated with UV or visible light. In a very similar MOF structure, Cu2(NDC)2(AzoBiPy), the experimental studies show an unexpected absence of photoisomerization. The DFT calculations reveal that in both MOFs the initial and final states of the photoswitching process (the trans and the cis conformation) have similar energies, which strongly suggests that the reason for the effective blocking of photoswitching in the AzoBiPy-based MOFs must be related to the switching process itself. More detailed calculations show that in Cu2(NDC)2(AzoBiPy) a naphthalene linker from the molecular framework blocks the photoisomerization trajectory which leads from the trans to the cis conformation. For Cu2(AzoBPDC)2(BiPy), as a result of the different geometry, such a steric hindrance is absent.

Pyridyl-substituted [2.2]paracyclophanes build am ultifunctional structural motif that is useful in material chemistry,c atalysis and for luminescent structures.N onetheless,t here is still al ack of general methodsf or the synthesiso ft hese structures tolerating easily accessiblebromides as well as different isomeric pyridyl groups.H ence the coupling of functionalized [2.2]paracyclophanes with various substituted andf unctionalized pyridyl derivatives was ach-ieved using Stille,S uzuki andK umada coupling conditions.H ereby the Stille coupling of a [2.2]paracyclophane is presenteda saversatile reaction for the formation of heteromeric [2.2]paracyclophane-containing biaryl structures.

The first example of a planar-chiral building block being used for chiral metal-organic frameworks (MOFs) is presented. The porous MOF structure combined with the chiral properties of the planar linker allows a selective adsorption, demonstrated for a nonpolar terpene limonene in thin surface-mounted MOF films.

The first synthesis of enantiomerically pure 4,7‐paracyclophane ditriflate starting from a quinone was reported. Using this molecule, mono‐ or dicoupling with boronic acids delivered enantiomerically pure arylparacyclophanes.

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